Double acting pump



Sept. 15, 1942- L. MCCONNOHIE 2,295,592

DOUBLE ACTING PUMP Filed Nov 1 1939 2 Sheets-Sheet l INVENTOR v L.L.McConnohle A TORNEY Patented Sept. 15, 1942 UNETED STATS OFFICE DOUBLE ACTING PUMP Levi L. McConnohie, Galesburg, Mich, assignor, by mesne assignments, to Bel-Mac Products Company,

Galesburg,

Mich, a partnership comprising H. V. Price, Carl R. Roelof, and Levi L. McConnohie 1 Claim.

The present invention relates broadly to pump mechanisms, and in its specific phases to double acting pumps.

The prior art pumps of the double acting type have almost universally been of special construction adapted for a limited specialized use. The early pumps of this type had to be completely submerged in the liquid to be pumped, and later when these pumps were adapted by subsequent inventors for use above the upper surface of the liquid to be pumped,'they were made with very complex piston and cylinder constructions. These cylinders were commonly cast with cored passageways, and in some instances with external valve chests containing the inlet valves for the cylinder. It was with these difficulties, complexities, limited use adaptability, and shortcomings of the prior art in mind that the present invention was devised.

Accordingly, among the objects of the present invention is the provision of a double acting pump adapted for a wide range of use and which is positive acting in operation and simplified so as to not be susceptible to the ready development of defects.

Another object of the present invention is to provide a double acting pump with the cylinder thereof mounted completely within an outer shell.

Another object is to provide each end of the cylinder with a closure member containing an inlet valve.

A further object is to provide a double acting pump having a pair of pistons mounted on the pump rod and spaced apart approximately half the length of the pump cylinder, each of said pistons being adapted for pumping action as it moves towards the outlet of the cylinder which is approximately at the midpoint of the side thereof.

A further object is to provide pistons, each of which has a body member with passageways therethrough and mounted so as to move in unison with the pump rod, said body member having mounted thereon an endwise sliding assembly adapted to seal against the cylinder wall and also act as a valve in connection with the body member to permit fluid to freely pass through said piston when the piston moves in its. non-pumping direction, and yet close this passageway promptly after starting the pumping stroke for this piston.

A further object is to provide a double acting pump which when mounted in vertical position will have a pair of valves in series to prevent leakage of fluid from the lower end of the pump cylinder assembly during intervals between use.

A further object is to provide a relatively noncomplex double acting pump which is simple to manufacture and assemble and ha an exceptionally high efl'lciency.

Further objects and advantages of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the means hereinafter fully described and particularly pointed out in the claim, the annexed drawings and the following description setting forth in detail certain means for carrying out the invention, such disclosed means illustrating, however, but several of various ways in which the principle of the invention may be used.

In said annexed drawings:

Figure 1 represents a side elevational view of one form of the double acting pump, together with an operating means therefor.

Figure 2 is a vertical sectional view showing one form of construction of the double acting pump of the present invention.

Figure 3 is a fragmentary detailed enlarged sectional view taken substantially on line 3'3 of Figure 2.

Figure 4 is a section taken along the line 4-4 of Figure 2.

Figure 5 is a section taken along the line 55 of Figure 2.

Figure 6 is a partially sectioned assembly view showing a modified construction for one end of the double acting'pump.

Figure 7 is a side elevational view of a preferred form of the piston body member.

Figure 8 is a section taken on the line 8-8 of Figure 7. I

Figure 9 is a vertical center section of a modified construction valve body member.

Figure 10 is a top View of the stop plate of the upper piston. I

Figure 11 is a bottom view'of the stop plate of the lower piston.

Figure 12 is a vertical sectional view showing a modified head plate construction for the double acting pump of the present invention.

The double acting pump of the present invention is adapted for a wide range of use, and same may be mounted for operation at various angles ranging from vertical to horizontal. The pump is also of compact, simple, and durable construction permitting easy assembly and ready disassembly and repair whenever necessary.

Referring more particularly to the drawings.

the double acting pump 5 (Figure l) is shown as fastened in vertical operating position by means of clamping members 6. Various mechanisms may be used for operating this pump and such may be changed as required. In the mechanism illustrated, a platform 1 is employed and has an electric motor 8 mounted thereon with driving pulley 9, which in turn by way of belt I8, drives the pulley II on shaft [2. This shaft l2 forms part of a gear reduction unit 13 in driving relation with flywheel l4 mounted on stub shaft I5 of the gear reduction unit. An eccentric pin IS on this flywheel l4 has the lower end of the pitman I1 connected thereto, while the upper end of the pitman is swivelly connected to collar 18 which is fixed on plunger rod I9, this plunger rod 19 operating through the guide 20 at the upper end of post 2|. This post 2| is suitably secured by a bracket or the like 22 to the frame or superstructure 23 supporting the geared reduction unit l3.

The double acting pump 5 (Figure 2) includes a tubular outer shell 24 which, for simplicity of construction, is preferably of cylindrical form. Within this outer shell 24 is mounted the pump cylinder 25 which is of smaller outside diameter than the internal size of outer shell 24 in order to provide a fluid passagewa 65 to the upper end of the cylinder, such passageway preferably being of sufficient size to permit free flow of fluid lengthwise thereof. Various means may be used for spacing the pump cylinder 25 from the inner walls of the outer shell 24, and one of the most convenient of these is to provide the outer shell on its inner circumference at the ends thereof with a plurality of knobs 26 and 21. Where the outer shell is made in the form of a casting, these knobs may be cast in place at the time the shell is produced in the mold. On the other hand, if the outer shell is to be made from pipe, these knobs may be welded or brazed in place. In preferred construction, the knobs are initially of a larger size than will permit the cylinder 25 to pass therebetween. Under these conditions, when the outer shell is machined to finish the ends thereof, preferably with step-cut shoulders 28 and 29 adapted to receive gaskets 38 and 3|, the inner edges 32 and 33 (Figures 4 and 5) of these knobs 25 and 21 are machined so that the pump cylinder 25 will snugly fit therebetween. With the pump cylinder 25 in place within outer shell 24, a convenient way of anchoring same against endwise displacement is to drill and thread a small hole in one or more of the knobs 26 and 21 at inner edges 32 and 33 and then place a screw or screws 34 (Figure 4) therein so as to threadedly engage both the knob and pump cylinder.

The double acting pump 5 is provided with upper and lower head caps 35 and 3B. The edges of these head caps, which abut the ends of outer shell 24, are preferably machined so as to fit step-cut shoulders 28 and 29 on the ends of outer shell 24 and seal on upper and lower gaskets 30 and 31. The step-cut construction of the head caps and ends of the outer shell embody one preferred form of construction, since it prevents side slippage of the head caps on the outer shell. The head caps may be joined to the outer shell in any conventional manner, but a preferred construction involves the use of upper and lower studs 31 and 38 adapted to pass through the ends of the upper and lower head caps, with gaskets 39 and 40 under the heads of said upper and lower studs to prevent leakage. In preferred construction, the upper and lower studs 31 and 38 are so located that upper and lower knobs 26 and 21 may be drilled and threaded at 4| and 42 to receive and engage the threaded ends of upper and lower studs 31 and 38 in manner such that the tightening of said studs will anchor the upper and lower head caps 35 and 38 on outer shell 34 with upper and lower gaskets 30 and 31 sealing the joints therebetween.

The lower head cap 36, where the double acting pump 5 is mounted above the upper level of the fluid to be pumped, as is shown in Figure 1, is provided with suitable threads 43 (Figure 2) or the equivalent for connection to an eduction pipe 44. The lower head cap is also provided with entrance ports 45 normally closed by a springheld check valve 46. The use of this check valve in series with the cylinder inlet valves presents the further advantage of a double seal against leakage during periods between use of the pump, a thing which is particularly important in overcoming pump priming trouble which is common with ordinary pumps where the piston has become worn from long use.

The upper head cap 35 (Figure 2) has mounted thereabove a spider 41 carrying on its upper end a ring member 48 in which a guide collar 49 for plunger rod I9 may be threadedly or otherwise anchored. The upper head cap 35 is also provided with a stufling box 58 having a conventional packing gland 5| and gasket 52. The lower end of the stufling box 50 is preferably elongated and threaded so as to engage corresponding threads in upper partition plate 53. This construction prevents leakage between compartment 96 and the interior of cylinder 25 at the entrance of plunger rod 19 thereinto, and at the same time avoids the necessity of a second stuffing box to accomplish this purpose.

The cylinder 25 is provided with upper and lower partition plates 53 and 54 (Figure 2) which may be fastened in place in conventional manner, one preferred construction involving the use of externall threaded partition plates adapted to threadedly engage corresponding threads on the inner circumference of the cylinder 25 at the ends thereof. Where water is to be pumped, the pump cylinder 25, upper and lower partition plates 53 and 54, and the valve mechanisms are preferably made of brass, since this facilitates satisfactory operation, as well as disassembly at any time it becomes necessary to make repairs or replacements. The particular kind of metal used for this purpose would, of course, be chosen in accordance with the service to which the pump would be subjected. The upper partition plate 53, as shown in Figure 2, is preferably centrally drilled and threaded for engagement with the correspondingly threaded lower end of stuffing box 50. drawing down of stufling box 58 into sealing engagement with gasket 52 to prevent leakage. The upper partition plate 53 is provided on its lower face with an inlet valve plate 55 of annular construction. This valve plate carries upwardly projecting stems 56 which loosely fit suitable openings through the upper partition plate 53 and each stem carries a spring means 51 which cooperates with same to normally hold the valve plate 55 in position closing inlet ports 58 in the partition plate.

The lower partition plate 54 has ports 59 therethrough which are normally closed on the upper side thereof by inlet valve plate 68. This valve plate 68 has a stem 0| freely fitting a sub- This construction facilitates the stantially central opening through the partition plate. A spring means 62 on stem 6| serves to normally hold valve plate 68 in position closing ports 59.

The outlet conductor 63 for the double acting pump 5. in preferred construction connects, with the interior of the pump cylinder 25 approximately at the midpoint of its length. A con venient construction for accomplishing this involves the provision of the pump cylinder 25 with an outwardly directed boss 64, the outer end of which is adapted to fit inside of outer shell 24 without interference which would cause distortion of the pump cylinder 25. The pump cylinder boss 64 and outer shell 24 may be predrilled at the outlet point if desired, but a more satisfactory procedure in general is to drill the opening after pump cylinder 25 has been assembled in place in outer shell 24. This provides a perfect alignment for the two openings which are then preferably taper threaded for the reception of the correspondingly taper-threaded end of the outlet conductor 63. The tightening of this conductor in place with sealing compound on the threads produces a fluid-tight joint which prevents leakage from or into the interior of pump cylinder 25, as well as passageway 65.

A pair of valved pistons 66 and 6'! (Figure 2) are provided on the plunger rod 19 at proper spaced intervals. These pistons go together to make up the plunger assembly which includes a suitable spacer member 68 between valved pistons 66 and 6! and adapted to be joined to the lower end of plunger rod la in conventional manner. A preferred construction of the plunger assembly is shown in Figure 3. Here spacer member 68a is shown as formed from a solid section of rod, the upper end of which is drilled and threaded for the reception of the threaded end 69 of plunger rod IS. The other end of spacer member 68a is drilled and threaded for the reception of screws 10. The body member ll of the upper piston is provided with longitudinal ports 12 with upper side openings I3 and a lower outwardly directed flange M. The upper portion of the body member H is provided with threaded openings 15 (Figure 8) adapted to receive suitable screws 8Q passing through openings IE (Figure of upper stop plate El. This stop plate is provided with a central opening 18 of a size permitting threaded end 68 of plunger rod is to pass therethrough. The upper piston 66 is provided with an endwise slidab-le annular member IS with outturned flange 88 carrying a packing element, for instance a cupshaped pump leather Bl, suitably fastened thereto in conventional manner such as by means of ring 82 and rivets 93, said packing element 8| overhanging outturned flange 86 in a downward direction.

In assemblin the upper piston 65 on the plunger assembly, the annular member 19 carrying packing element 8| is first placed on the body member ll with the free edge of the packing element extending in the same direction as annular 1 member 19 has been moved in the placing of same on body member ll. Upper stop plate H is then placed on the end of body member II opposite to flange i l. The openings 16 in upper stop plate I! are then aligned with threaded openings in body member H and screws 34 applied and tightened in place. The upper valved piston assembly 66 is then slipped over the upper end of spacer member 68a and the threaded end 69 of plunger rod l9 screwed into place and tightened to holdthe upper piston assembly in desired position. 7

The lower valved piston assembly 61 is as-, sembled in the same manner as described above in connection with the upper valved piston assembly 66 with the exception that in the place of upper stop plate 11, lower stop plate is used. The openings 16a in this lower stop plate 85 are identical with those in the upper stop plate 11, and screws 84 are used for fastening same to body member H of the valved piston. The so-assembled; valved piston 61 is slipped onto the lower end of spacer member 68a so as to be inverted relative to valved piston 66, following which screws i8 are passed through openings 86 in lower stop plate 35, and the whole fastened thereby to the lower end of spacer member 66a.

A modified construction valve body member Ha is shown in Figure 9. In this construction a tight slip. fit of the body member over spacer member 68 is eliminated, and to take care of centering the piston, the body member I la thereof is provided with a top panel 81 having an opening 33 therethrough for the reception of threaded end 69 of plunger rod is when the body member Ha is used as part of the upper valved piston. The same annular member 19 with packing element 8! is used and so isthe upper stop plate 11. However, in this case, the openings 16 therein are unnecessary, since the top panel 81 acts to hold the valved body member I la from endwise movement on spacer member 68. The same valved body member Fla is likewise usable as part of the lower valved piston 61 with the modification, if necessary, of opening 88, to adapt it to the particular means chosen for anchoring the lower valved piston the proper side up and centrally of the lower end of spacer member 68.

A modified construction for the double acting pump and which avoids the use of knobs 26 and 2] on the inner face of outer shell 24 is shown in Figure 12. In this construction, upper and lower partition plates 53a and 54a are made of larger diameter and threaded on their outer periphery to engage corresponding threads 90 and 9! on the inner face of outer shell Zea at the ends thereof. The inner faces of upper and lower partition plates 53a and 54a are provided with annular grooves 92 and 93 respectively for receiving and closely fitting the upper and lower ends of pump cylinder 25a and holding the pump cylinder in spaced relation with respect to outer shell 24a to the end. that a passageway 65 is defined between the shell and cylinder. To provide for ingress and egress of fluid passing through passageway 65, upper and lower partition plates 53a and 54a are each provided with a plurality of ports 94 and 95 respectively. Upper and lower head caps 35a and 36a may be threadedly engaged over the upper and lower ends of outer shell 24a to define compartments 96a and 91a which are in communication with passageway 65 by way of ports 94 and 95. as Well as upper and lower partition plate inlet ports 58a and 59a which lead to the interior of pump cylinder 25a when the valves, including valve plates 55a and 68a respectively, are open.

The double acting pump of the present inven-- tion obviously is not limited to use in any one position or location, although one form of mounting above ground is illustrated in Figure 1. Where the pump is to be used in connection with wells in localities subject to freezing conditions, it is commonly desirable to lower the double acting pump cylinder assembly into the well itself a sufficient distance below ground level to protect same from freezing, This may be readily accomplished by removing guide collar 49 from upper head cap 35 (Figure 2) and substituting therefor pipe 89 (Figure 6) through which plung-v er rod l9 may freely move. The upper end of pipe 89 may be anchored in conventional manner to support the double acting pump 5 at the desired elevation within the well itself.

The operation of the pump when pumping water is as follows: The movement of plunger rod IS in a downward direction causes the body member H of both of the valved pistons 66 and 6"! to move downward relative to the slidable annular members 19 carrying packing element 8|. This results in closing the upper side openings 13 of longitudinal ports 12 of the upper valved piston 66. At the same time, side openings 13 of longitudinal ports 12 of the lower valved piston 61 will be opened. Construction of the piston assembly as shown presents the advantage of positive operation in opening and closing the ports through the piston due to contact of packing member BI on cylinder 25 which permits body member TI to move endwise relative to packing member 8!, while the latter remains motionless, thus operating as an opener and closer for the piston ports without requiring springs, spring anchors, et cetera, which not only increase the cost of the pump and act as a further source of trouble, but also act to retard flow and hence increase the power required to pump a given quantity of fluid. Continued movement of the plunger rod assembly results in the upper piston exerting suction thereabove and pressure therebelow, while water below lower valved piston 61 freely flows through the ports thereof into the space above same. Under these conditions, the spring actuated valve plate 66 mounted on the inner face of lower partition plate 54 will be closed, while the spring actuated valve plate 55 on the under face of upper partition plate 53 will be open as will be spring actuated check valve 46 in lower head cap 36. With the pump cylinder 25 full of water, continued downward movement of plunger rod I9 will force water out through outlet conductor 63 to a, point of use or the like. Upon reverse movement of plunger rod l9, side openings 13 of longitudinal ports 12 of the upper valved piston 66 will open, while the corresponding ports and openings of the lower valved piston 61 will be closed due to movement of the body member portions of these two valves in an upward direction relative to the slidable packing element carrying portion of the pistons. Under these conditions, upon upward movement of plunger rod I9, water above the upper valved piston 66 will freely flow through the valved portion thereof to the under side of the piston. At the same time, lower valved piston 61 will have its passageways closed and will be exerting suction on the under side thereof and pressure on its upper side to force water out of outlet conductor 63 so long as upward movement of plunger rod I9 is continued and lower valved piston 61 is approaching outlet 63. During this upward movement of plunger rod I9, spring actuated valve plate 55 in upper partition plate 53 will be closed, while spring actuated valve plate 66 in lower partition plate 54 will be opened, as will be spring actuated valve plate 46 in lower head cap 36, the opening of the latter two valves permitting water to flow into the lower end of cylinder 25 in response to the suction exerted by the upward movement of lower valved piston 61. Upon again reversing the direction of movement of plunger rod [9, Water will flow through passageway 65, compartment 96 in upper head cap 35, and inlet ports 58 into the upper end of cylinder 25 in response to the suction exerted due to the downward movement of upper valved piston 66, this procedure alternating in continuous manner in step with the longitudinal movement of the plunger assembly within the cylinder.

Other modes of applying the principle of my invention may be employed instead of those ex-.- plained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

A double acting pump which consists of an outer shell, a cylinder in the shell in spaced relation thereto, partitions for the ends of said cylinder and threadably engaging the latter, said partitions having ports therein, inlet valves for said ports, an outlet from said cylinder, headers for the shell, said headers communicating the ports in the cylinder partitions with the space between the outer shell and the cylinder, a plunger rod operative into the cylinder and passing through one of said end partitions and header, stufling box means for said plunger rod where it passes through said partition and header, said stuffing box means joining the header with the adjacent partition to prevent leakage through said stufiing box means from the space between said header and partition while increasing resistance to fluid leakage from the cylinder and providing a better bearing for said plunger rod, a pair of valved pistons carried by said plunger rod and spaced apart a distance approximately equal to one-half the length of the cylinder, each of said valved pistons comprising an apertured member fixedly mounted in connection with said plunger rod for movement in unison therewith, an annular shaped means with cylinder wall contacting packing member, said annular shaped means being adapted to be moved endwise within said cylinder and to slide on said apertured member, stop means on said apertured member for limiting the extent of endwise movement of said annular means on said apertured member, the apertured member, stop means, and annular shaped means of said piston cooperating to close the apertures through the apertured member on which same is mounted, during pumping movement of that piston and to open same for fluid flow therethrough upon reverse movement of said piston, said pistons being mounted in connection with said plunger rod for pumping action by each individual piston as it approaches the cylinder outlet, said outlet from said cylinder being located at a point approximately midway of the length thereof, the header opposite to the one through which the plunger rod passes acting as the inlet of the cylinder assembly for connection to a suitable source of fluid supply, and an inlet check Valve in said last named header.

LEVI L. MCCONNOHIE. 

